diff --git a/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinBuilder.kt b/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinBuilder.kt
index 0658069ddef..5905b0899f6 100644
--- a/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinBuilder.kt
+++ b/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinBuilder.kt
@@ -158,7 +158,7 @@ public class KotlinBuilder : ModuleLevelBuilder(BuilderCategory.SOURCE_PROCESSOR
 
         val lookupTracker =
                 project.container.getChild(LOOKUP_TRACKER)?.let {
-                    assert("true".equals(System.getProperty("kotlin.jps.tests"), ignoreCase = true), "LOOKUP_TRACKER allowed only for jps tests")
+                    assert("true".equals(System.getProperty("kotlin.jps.tests"), ignoreCase = true)) { "LOOKUP_TRACKER allowed only for jps tests" }
                     it.data
                 } ?: LookupTracker.DO_NOTHING
 
diff --git a/jps/jps-plugin/test/org/jetbrains/kotlin/jps/build/KotlinJpsBuildTest.kt b/jps/jps-plugin/test/org/jetbrains/kotlin/jps/build/KotlinJpsBuildTest.kt
index c41e3a5e127..3adf53cfde1 100644
--- a/jps/jps-plugin/test/org/jetbrains/kotlin/jps/build/KotlinJpsBuildTest.kt
+++ b/jps/jps-plugin/test/org/jetbrains/kotlin/jps/build/KotlinJpsBuildTest.kt
@@ -549,7 +549,7 @@ public class KotlinJpsBuildTest : AbstractKotlinJpsBuildTestCase() {
         val result = HashSet<String>()
         for (file in files) {
             val relativePath = FileUtil.getRelativePath(baseDir, file)
-            assert(relativePath != null, "relativePath should not be null")
+            assert(relativePath != null) { "relativePath should not be null" }
             result.add(toSystemIndependentName(relativePath!!))
         }
         return result
@@ -581,7 +581,7 @@ public class KotlinJpsBuildTest : AbstractKotlinJpsBuildTestCase() {
 
         assertCanceled(buildResult)
         buildResult.assertSuccessful()
-        assert(interval < 8000, "expected time for canceled compilation < 8000 ms, but $interval")
+        assert(interval < 8000) { "expected time for canceled compilation < 8000 ms, but $interval" }
 
         val module = myProject.getModules().get(0)
         assertFilesNotExistInOutput(module, "foo/Foo.class")